org.codehaus.groovy.grails.web.json
[Java] Class JSONObject

java.lang.Object
  org.codehaus.groovy.grails.web.json.JSONObject

All Implemented Interfaces:

JSONElement, java.util.Map

@SuppressWarnings({ "unchecked", "rawtypes" })
public class JSONObject
extends java.lang.Object

A JSONObject is an unordered collection of name/value pairs. Its external form is a string wrapped in curly braces with colons between the names and values, and commas between the values and names. The internal form is an object having get and opt methods for accessing the values by name, and put methods for adding or replacing values by name. The values can be any of these types: Boolean, JSONArray, JSONObject, Number, String, or the JSONObject.NULL object. A JSONObject constructor can be used to convert an external form JSON text into an internal form whose values can be retrieved with the get and opt methods, or to convert values into a JSON text using the put and toString methods. A get method returns a value if one can be found, and throws an exception if one cannot be found. An opt method returns a default value instead of throwing an exception, and so is useful for obtaining optional values.

The generic get() and opt() methods return an object, which you can cast or query for type. There are also typed get and opt methods that do type checking and type coersion for you.

The put methods adds values to an object. For example,

     myString = new JSONObject().put("JSON", "Hello, World!").toString();

The texts produced by the toString methods strictly conform to the JSON sysntax rules. The constructors are more forgiving in the texts they will accept:

• An extra , (comma) may appear just before the closing brace.
• Strings may be quoted with ' (single quote).
• Strings do not need to be quoted at all if they do not begin with a quote or single quote, and if they do not contain leading or trailing spaces, and if they do not contain any of these characters: { } [ ] / \ : , = ; # and if they do not look like numbers and if they are not the reserved words true, false, or null.
• Keys can be followed by = or => as well as by :.
• Values can be followed by ; (semicolon) as well as by , (comma).
• Numbers may have the 0- (octal) or 0x- (hex) prefix.
• Comments written in the slashshlash, slashstar, and hash conventions will be ignored.

Authors:

JSON.org

Version:

2

NULL

public static final java.lang.Object NULL

It is sometimes more convenient and less ambiguous to have a NULL object than to use Java's null value. JSONObject.NULL.equals(null) returns true. JSONObject.NULL.toString() returns "null".

JSONObject

public java.lang.Object JSONObject()

Construct an empty JSONObject.

JSONObject

public java.lang.Object JSONObject(JSONObject jo, java.lang.String[] sa)

Construct a JSONObject from a subset of another JSONObject. An array of strings is used to identify the keys that should be copied. Missing keys are ignored.

throws:

JSONException If a value is a non-finite number.

Parameters:

jo - A JSONObject.

sa - An array of strings.

JSONObject

public java.lang.Object JSONObject(JSONTokener x)

Construct a JSONObject from a JSONTokener.

throws:

JSONException If there is a syntax error in the source string.

Parameters:

x - A JSONTokener object containing the source string.

JSONObject

public java.lang.Object JSONObject(java.util.Map map)

Construct a JSONObject from a Map.

Parameters:

map - A map object that can be used to initialize the contents of the JSONObject.

JSONObject

public java.lang.Object JSONObject(java.lang.String string)

Construct a JSONObject from a string. This is the most commonly used JSONObject constructor.

throws:

JSONException If there is a syntax error in the source string.

Parameters:

string - A string beginning with { (left brace) and ending with } (right brace).

accumulate

public JSONObject accumulate(java.lang.String key, java.lang.Object value)

Accumulate values under a key. It is similar to the put method except that if there is already an object stored under the key then a JSONArray is stored under the key to hold all of the accumulated values. If there is already a JSONArray, then the new value is appended to it. In contrast, the put method replaces the previous value.

throws:

JSONException If the value is an invalid number or if the key is null.

Parameters:

key - A key string.

value - An object to be accumulated under the key.

Returns:

this

clear

public void clear()

containsKey

public boolean containsKey(java.lang.Object o)

containsValue

public boolean containsValue(java.lang.Object o)

dateToString

public static java.lang.String dateToString(java.util.Date d)

entrySet

public java.util.Set entrySet()

equals

@Override
public boolean equals(java.lang.Object o)

get

public java.lang.Object get(java.lang.String key)

Get the value object associated with a key.

throws:

JSONException if the key is not found.

Parameters:

key - A key string.

Returns:

The object associated with the key.

get

public java.lang.Object get(java.lang.Object o)

getBoolean

public boolean getBoolean(java.lang.String key)

Get the boolean value associated with a key.

throws:

JSONException if the value is not a Boolean or the String "true" or "false".

Parameters:

key - A key string.

Returns:

The truth.

getDouble

public double getDouble(java.lang.String key)

Get the double value associated with a key.

throws:

JSONException if the key is not found or if the value is not a Number object and cannot be converted to a number.

Parameters:

key - A key string.

Returns:

The numeric value.

getInt

public int getInt(java.lang.String key)

Get the int value associated with a key. If the number value is too large for an int, it will be clipped.

throws:

JSONException if the key is not found or if the value cannot be converted to an integer.

Parameters:

key - A key string.

Returns:

The integer value.

getJSONArray

public JSONArray getJSONArray(java.lang.String key)

Get the JSONArray value associated with a key.

throws:

JSONException if the key is not found or if the value is not a JSONArray.

Parameters:

key - A key string.

Returns:

A JSONArray which is the value.

getJSONObject

public JSONObject getJSONObject(java.lang.String key)

Get the JSONObject value associated with a key.

throws:

JSONException if the key is not found or if the value is not a JSONObject.

Parameters:

key - A key string.

Returns:

A JSONObject which is the value.

getLong

public long getLong(java.lang.String key)

Get the long value associated with a key. If the number value is too long for a long, it will be clipped.

throws:

JSONException if the key is not found or if the value cannot be converted to a long.

Parameters:

key - A key string.

Returns:

The long value.

getString

public java.lang.String getString(java.lang.String key)

Get the string associated with a key.

throws:

JSONException if the key is not found.

Parameters:

key - A key string.

Returns:

A string which is the value.

has

public boolean has(java.lang.String key)

Determine if the JSONObject contains a specific key.

Parameters:

key - A key string.

Returns:

true if the key exists in the JSONObject.

hashCode

@Override
public int hashCode()

isEmpty

public boolean isEmpty()

isNull

public boolean isNull(java.lang.String key)

Determine if the value associated with the key is null or if there is no value.

Parameters:

key - A key string.

Returns:

true if there is no value associated with the key or if the value is the JSONObject.NULL object.

keySet

public java.util.Set keySet()

keys

public java.util.Iterator keys()

Get an enumeration of the keys of the JSONObject.

Returns:

An iterator of the keys.

length

public int length()

Get the number of keys stored in the JSONObject.

Returns:

The number of keys in the JSONObject.

names

public JSONArray names()

Produce a JSONArray containing the names of the elements of this JSONObject.

Returns:

A JSONArray containing the key strings, or null if the JSONObject is empty.

numberToString

public static java.lang.String numberToString(java.lang.Number n)

Produce a string from a number.

throws:

JSONException If n is a non-finite number.

Parameters:

n - A Number

Returns:

A String.

opt

public java.lang.Object opt(java.lang.String key)

Get an optional value associated with a key.

Parameters:

key - A key string.

Returns:

An object which is the value, or null if there is no value.

optBoolean

public boolean optBoolean(java.lang.String key)

Get an optional boolean associated with a key. It returns false if there is no such key, or if the value is not Boolean.TRUE or the String "true".

Parameters:

key - A key string.

Returns:

The truth.

optBoolean

public boolean optBoolean(java.lang.String key, boolean defaultValue)

Get an optional boolean associated with a key. It returns the defaultValue if there is no such key, or if it is not a Boolean or the String "true" or "false" (case insensitive).

Parameters:

key - A key string.

defaultValue - The default.

Returns:

The truth.

optDouble

public double optDouble(java.lang.String key)

Get an optional double associated with a key, or NaN if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A string which is the key.

Returns:

An object which is the value.

optDouble

public double optDouble(java.lang.String key, double defaultValue)

Get an optional double associated with a key, or the defaultValue if there is no such key or if its value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

An object which is the value.

optInt

public int optInt(java.lang.String key)

Get an optional int value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

Returns:

An object which is the value.

optInt

public int optInt(java.lang.String key, int defaultValue)

Get an optional int value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

An object which is the value.

optJSONArray

public JSONArray optJSONArray(java.lang.String key)

Get an optional JSONArray associated with a key. It returns null if there is no such key, or if its value is not a JSONArray.

Parameters:

key - A key string.

Returns:

A JSONArray which is the value.

optJSONObject

public JSONObject optJSONObject(java.lang.String key)

Get an optional JSONObject associated with a key. It returns null if there is no such key, or if its value is not a JSONObject.

Parameters:

key - A key string.

Returns:

A JSONObject which is the value.

optLong

public long optLong(java.lang.String key)

Get an optional long value associated with a key, or zero if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

Returns:

An object which is the value.

optLong

public long optLong(java.lang.String key, long defaultValue)

Get an optional long value associated with a key, or the default if there is no such key or if the value is not a number. If the value is a string, an attempt will be made to evaluate it as a number.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

An object which is the value.

optString

public java.lang.String optString(java.lang.String key)

Get an optional string associated with a key. It returns an empty string if there is no such key. If the value is not a string and is not null, then it is coverted to a string.

Parameters:

key - A key string.

Returns:

A string which is the value.

optString

public java.lang.String optString(java.lang.String key, java.lang.String defaultValue)

Get an optional string associated with a key. It returns the defaultValue if there is no such key.

Parameters:

key - A key string.

defaultValue - The default.

Returns:

A string which is the value.

put

public JSONObject put(java.lang.String key, boolean value)

Put a key/boolean pair in the JSONObject.

throws:

JSONException If the key is null.

Parameters:

key - A key string.

value - A boolean which is the value.

Returns:

this

put

public JSONObject put(java.lang.String key, double value)

Put a key/double pair in the JSONObject.

throws:

JSONException If the key is null or if the number is invalid.

Parameters:

key - A key string.

value - A double which is the value.

Returns:

this

put

public JSONObject put(java.lang.String key, int value)

Put a key/int pair in the JSONObject.

throws:

JSONException If the key is null.

Parameters:

key - A key string.

value - An int which is the value.

Returns:

this

put

public JSONObject put(java.lang.String key, long value)

Put a key/long pair in the JSONObject.

throws:

JSONException If the key is null.

Parameters:

key - A key string.

value - A long which is the value.

Returns:

this

put

public JSONObject put(java.lang.String key, java.lang.Object value)

Put a key/value pair in the JSONObject. If the value is null, then the key will be removed from the JSONObject if it is present.

throws:

JSONException If the value is non-finite number or if the key is null.

Parameters:

key - A key string.

value - An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, Long, String, or the JSONObject.NULL object.

Returns:

this

put

public java.lang.Object put(java.lang.Object o, java.lang.Object o1)

putAll

public void putAll(java.util.Map map)

putOpt

public JSONObject putOpt(java.lang.String key, java.lang.Object value)

Put a key/value pair in the JSONObject, but only if the key and the value are both non-null.

throws:

JSONException If the value is a non-finite number.

Parameters:

key - A key string.

value - An object which is the value. It should be of one of these types: Boolean, Double, Integer, JSONArray, JSONObject, Long, String, or the JSONObject.NULL object.

Returns:

this

quote

public static java.lang.String quote(java.lang.String string)

Produce a string in double quotes with backslash sequences in all the right places. A backslash will be inserted within

Parameters:

string - A String

Returns:

A String correctly formatted for insertion in a JSON text.

remove

public java.lang.Object remove(java.lang.String key)

Remove a name and its value, if present.

Parameters:

key - The name to be removed.

Returns:

The value that was associated with the name, or null if there was no value.

remove

public java.lang.Object remove(java.lang.Object o)

size

public int size()

toJSONArray

public JSONArray toJSONArray(JSONArray names)

Produce a JSONArray containing the values of the members of this JSONObject.

throws:

JSONException If any of the values are non-finite numbers.

Parameters:

names - A JSONArray containing a list of key strings. This determines the sequence of the values in the result.

Returns:

A JSONArray of values.

toString

@Override
public java.lang.String toString()

Make an JSON text of this JSONObject. For compactness, no whitespace is added. If this would not result in a syntactically correct JSON text, then null will be returned instead.

Warning: This method assumes that the data structure is acyclical.

Returns:

a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

toString

public java.lang.String toString(int indentFactor)

Make a prettyprinted JSON text of this JSONObject.

Warning: This method assumes that the data structure is acyclical.

throws:

JSONException If the object contains an invalid number.

Parameters:

indentFactor - The number of spaces to add to each level of indentation.

Returns:

a printable, displayable, portable, transmittable representation of the object, beginning with { (left brace) and ending with } (right brace).

values

public java.util.Collection values()

write

public java.io.Writer write(java.io.Writer writer)

Write the contents of the JSONObject as JSON text to a writer. For compactness, no whitespace is added.

Warning: This method assumes that the data structure is acyclical.

throws:

JSONException

Returns:

The writer.

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